The present application relates to an angular velocity sensor used for, for example, a hand jiggle detection when a video camera is used, an operation detection in a virtual reality apparatus, and a direction detection in a car navigation system, and to a method of manufacturing the same.
In related art, as a consumer angular velocity sensor, there is being used a so-called vibrating gyro sensor (hereinafter, referred to as angular velocity sensor) that detects an angular velocity by detecting Coriolis force generated due to an influence of an angular velocity by using a piezoelectric element or the like while a cantilever or double-end-beam vibrator, a tuning fork vibrator, and the like are vibrated at a predetermined resonant frequency.
An angular velocity sensor has advantages in its simple structure, short start-up time, and low-cost manufacturability. Electronic apparatuses such as a video camera, a virtual reality apparatus, and a car navigation system are equipped with an angular velocity sensor, which is used as a sensor for a hand jiggle detection, an operation detection, a direction detection, or the like.
Along with miniaturization and enhanced performance of an electronic apparatus equipped with an angular velocity sensor, there is a demand for an angular velocity sensor to be reduced in size and enhanced in performance. Specifically, for a multifunctional electronic apparatus, an angular velocity sensor is required to be mounted on a single substrate in combination with various sensors used for other purposes, to realize the size reduction.
In related art, generally, a gyro sensor having a structure in which a piezoelectric material such as PZT (lead zirconate titanate) is processed into flakes by machining, retained by a spring or the like, and vibrated by applying an electrical signal has been used, but is difficult to be miniaturized.
In view of this, the following technique has been developed. A single-crystalline substrate made of, for example, Si (silicon) is used, a piezoelectric material such as PZT (lead zirconate titanate) is formed into a thin film on the substrate by a sputtering method or a sol-gel method, and an etching process is performed on a predetermined part of the substrate, thereby producing a plurality of vibrators each of which is a quadrangular prism and has a rectangular cross-section from the single substrate at the same time (see, for example, Japanese Patent Application Laid-open No. 2007-43054, hereinafter, referred to as Patent Document 1).